1. Field of the Invention (Technical Field)
The present invention relates to wireless communication between electronic circuit boards and between circuit components on circuit boards.
2. Background Art
Printed circuit boards provide for the interconnection of a variety of electronic components such as integrated circuits (ICs), application specific integrated circuits (ASICs), and programmable logic devices (PLDs). Communication amongst these components is typically accomplished through etched copper traces in the circuit board. These fixed communication paths limit the flexibility of a given circuit board design, even if implemented with the latest programmable logic devices, to be reconfigured for multiple uses. Changes in the communication paths require redesign and manufacturing of a new circuit board, an expensive and time consuming proposition.
Communication between individual printed circuit boards is achieved by hardwiring one board to the next with conductive wires and mechanical connectors that connect input and output (I/O) pins on one circuit board to the next. As more data is moved between printed circuit boards at higher transmission rates, board-to-board communication becomes increasingly difficult. A high number of I/O pins in connectors having limited space can lead to connector failure, and a high density of I/O pins operating at high speeds can lead to crosstalk and errors between data lines.
One limitation encountered in printed circuit wiring technology and wire connections from one circuit board to the next is that the transmission paths from one electronic component to the next or from one circuit board to the next, once defined, cannot change. The etched copper traces and the wiring configurations are established during the manufacturing process and these paths then remain fixed. Highly integrated PLDs have been developed to combat the problem of hard coded digital logic in digital logic gates, but these devices offer only a partial solution to the problem of inflexible interconnects. A solution is needed that provides reconfigurable interconnects amongst electronic components on circuit boards as well as between circuit boards so that the destination of transmitted information can be controlled, and communication made more efficient.
One method of communicating electrical signals from one circuit board to the next is by free space optical communications. Free space optical communications, such as laser communication, eliminate the need for etched copper traces or hardwire connections, thereby increasing the reconfigurability of the communication transmission path. However, while these techniques have been demonstrated, they are inherently difficult to implement because of the need for tight alignment tolerances between sending and receiving units. There must be a clear transmission path from the transmitter to the receiver to inhibit interference so that the receiver can accurately receive the transmission.
One type of communication scheme that is typically used for communicating over extended distances includes radio frequency (RF) communications. Radio frequencies are used to transmit information from one remote location to another, such as from a radio station transmitter to an individual radio. Basically, a transmitter transmits a modulated signal at radio frequencies to a receiver that receives and demodulates the signal into a frequency band that can be used to communicate information in the signal to the receiving entity. For example, the received signal may be converted into an electrical signal for transmission to an audio speaker.
With the advent of silicon integrated circuits, it is now possible to reduce RF transceiver circuitry into single chip components. This has enabled the use of RF communications for digital data exchange between small hand-held devices such as Personal Data Assistants (PDAs). These same components can be used to provide reconfigurable communication routing between electronic components on circuit boards and between circuit boards.
Complex communication systems, whether RF or conventional communication systems on and across circuit boards, require management of information flow. A variety of protocols have evolved to control signal routing and flow. The asynchronous transfer mode (ATM) communication protocol is one such methodology for controlling communication flow between two or more sites. ATM networks are more fully described in: Martin DePrycker, Asynchronous Transfer Mode, 2nd Edition, Ellis Horwood, Ltd. (1993), and Abhijit S. Pandya and Ercan Sen, ATM Technology for Broadband Networks, CRC Press (1999). The entire disclosures of these references are herein incorporated by reference.
The present invention solves the problems encountered in prior art circuit board communication by implementing low power RF as the communication means, thereby enabling reconfigurable communication paths between circuit boards and between electronic circuit components on circuit boards. An ATM protocol is used to control communication flow.